Endophenotypes in Psychiatry
This journal is the first to be briefly reviewed, and has been chosen due to its relation to the early thoughts of dissertation topic planning.
Endophenotypes are an interesting concept in Psychiatry for many reasons; this paper introduces a well-known rationale - our current diagnostic processes are inadequate.
The paper provides a compilation of various definitions by various authors, each adding a snippet to our understanding of what an endophenotype includes or involves rather than what is definitively is. It then goes on to look at why/how endophenotypes would be used in research, and lastly, a realistic summary or the dangers and future directions.
Definition - so to speak...
An endophenotype is heritable, and is seen:
1. At a higher rate in the affected individual than in healthy relatives
2. At a higher rate in healthy relatives than in the general population.
The paper states the central assumption that genetic analysis is possible because a variation in this endophenotype will involve much fewer, identifiable genes than the overall disorder phenotype. It was importantly noted that it is state independent, i.e. present in an affected individual even if their diagnosis is in remission.
The clearest reference guide for what an endophenotype is has been described by Gottesman and Shield (the pioneers of this term), as
‘internal phenotypes that lie on the pathway between genes and disease’.
This is simplistic and has since been clarified as just one presentation of endophenotypes in Psychiatry, as demonstrated in the image below. these options were laid out a s Nonetheless this definition puts perspective and context on a still fairly new concept.
Walters, J.T.R. & Owen, M.J., 2007. Endophenotypes in psychiatric genetics. Molecular psychiatry, 12, pp.886–890.
